kathykavan.com

"Rail Alphabet is a typeface designed by Jock Kinneir and Margaret Calvert for British Railways. First used by them in signing tests at London's Liverpool Street Station, it was then adopted by the Design Research Unit (DRU) as part of their comprehensive 1965 rebranding of the company. Rail Alphabet is similar, but not identical, to a bold weight of Helvetica (and, not quite as similar, Akzidenz Grotesk or Arial). Akzidenz Grotesk had earlier also provided the same designers the broad inspiration for the Transport typeface used for all road signs in the United Kingdom." http://en.wikipedia.org/wiki/Rail_Alphabet